This invention relates generally to devices for interventional therapeutic treatment or vascular surgery for treatment of defects in the vasculature, and more particularly concerns a system and method for delivering intravascular interventional devices, such as for treatment of aneurysms.
Vascular interventional devices such as vasoocclusive devices are typically placed within the vasculature of the human body by use of a catheter. Vascular interventional devices such as stents can be placed within an occluded vessel to facilitate blood flow through the vessel, and vasoocclusive devices are typically either placed within a blood vessel to block the flow of blood through a vessel making up that portion of the vasculature through the formation of an embolus, or are placed within an aneurysm stemming from the vessel to form such an embolus within the aneurysm. Stents can have a wide variety of configurations, but generally need to be placed and then released at a desired location within a blood vessel. Vasoocclusive devices used for these procedures can also have a wide variety of configurations, and aneurysms have been treated with external surgically placed clips, detachable vasoocclusive balloons and embolus generating vasoocclusive devices such as one or more vasoocclusive or embolic coils.
The delivery of such vasoocclusive devices has typically been accomplished by a variety of means, including via a catheter in which the device is pushed through an opening at the distal end of the catheter by a pusher to deploy the device. The vasoocclusive devices can be produced in such a way that they will pass through the lumen of a catheter in a linear shape and take on a complex shape as originally formed after being deployed into the area of interest, such as an aneurysm.
Detachable vasoocclusive devices are typically embolic coils fixed to a distal end of a flexible pusher member for delivery of the embolic coils, and may be detached mechanically, electrically or by some other means from the flexible pusher member at the target location. The detachable embolic coils can be delivered to the target location and detached if correctly sized and positioned, or may be withdrawn without being detached if the coils are not correctly sized, are not correctly positioned, or microcatheter positioning is lost. Some available vasoocclusive devices are not reused during a patient procedure if they are removed during the procedure, due to the inability to reload the device into the microcatheter. It would be desirable to provide a system and method for reusing vasoocclusive devices during a clinical procedure after removal from a microcatheter introducer. The present invention meets these and other needs.
Briefly, and in general terms, the present invention provides for an introducer sheath for vasoocclusive devices that can be loaded onto a vasoocclusive embolic coil assembly after removal of the vasoocclusive embolic coil assembly from a microcatheter, to permit reuse of the vasoocclusive embolic coil assembly during a clinical procedure and to minimize the loss of an otherwise acceptable vasoocclusive embolic coil product.
The present invention accordingly provides for a sheath for a therapeutic vasoocclusive device which includes an assembly of a flexible pusher member and an embolic coil. The sheath includes a hollow, elongated tubular member having opposing upper and lower walls, opposing side walls, and a longitudinal interior channel, and a longitudinal slot formed in the upper wall of the elongated tubular member and extending the length, or majority of the length, of elongated tubular member. The slot has opposing sides with inner side surfaces extending through the upper wall of the elongated tubular member leading to the interior channel permitting introduction of the vasoocclusive device into the interior channel. In one aspect, the upper wall of the elongated tubular member adjacent to the slot has an angled configuration on the outside surface of the hollow, elongated tubular member. The angled configuration on the outside surface of the hollow, elongated tubular member has opposing exterior surfaces forming an interior angle of typically about 110xc2x0 to 150xc2x0.
In another aspect, the lower wall of the hollow, elongated tubular member is about 0.002 to 0.004 inches thick to allow the opposing sides of the slot of the hollow, elongated tubular member to flex outwardly to allow the slot to open to accept the vasoocclusive device. The hollow, elongated tubular member may be formed from a thermoplastic material, such as high density polyethylene, for example.
In one embodiment, the sheath may further include wing members extending outwardly from the angled configuration on the outside surface of the hollow, elongated tubular member to facilitate insertion of the vasoocclusive device into the sheath. The wing members of the angled configuration on the outside surface of the hollow, elongated tubular member have opposing exterior surfaces typically forming an interior angle of about 110xc2x0 to 150xc2x0. In a variation of these embodiments, the sheath may be formed in combination with the vasoocclusive device, the elongated tubular member consisting of a length with no slot attached to a segment of the flexible pusher member to facilitate initiation of loading of the flexible pusher member and embolic coil into the sheath.
These and other aspects and advantages of the invention will become apparent from the following detailed description and the accompanying drawings, which illustrate by way of example the features of the invention.